The present application relates to knives, in particular to a knife that may extend a blade from, and subsequently retract the blade into, the body of the knife.
The use of knives by workmen is widespread, and many knives have been developed to improve upon the safe usage thereof. In particular, many solutions have been developed to the problem of safely storing the blade of a knife once it has been used.
Some knives allow the user to pivotably fold the blade into a compartment in the handle of the knife, so that the cutting edge of the blade is concealed and does not present a danger of accidental injury. A problem with such a folding knife is that it typically takes two hands to operate the blade opening and closing actions, particularly when it comes to opening the blade from a closed position.
Other knives have been developed that allow a blade to slide axially forward from a storage position within the knife to extend from the front end of the knife, and to subsequently axially retract back into the body of the knife when the blade has been used. These knives are typically operated by pressure sensitive elements on the handle of the knife manipulable by a thumb or forefinger. However, such knives typically may also require two different pressure sensitive elements, one for opening and one for closing the blade.
Some knives have been developed in which only one pressure sensitive element is provided for both opening and closing the blade. However, in such knives it is typical for example for a forward motion on the element to open the blade, and a backward motion on the element to close the blade. This has the disadvantage of introducing multiple hand actions for a user to apply. Moreover, such knives rely on complex internal mechanisms to achieve this effect.
Yet, circumstances frequently may require the maximum simplicity, namely a single consistent hand movement for both opening and closing operations because workmen are frequently obliged to work in confined circumstances where complex manual actions are difficult. Thus, there is a need in the art for a knife that is extremely simple to operate, simple and inexpensive to manufacture and assemble, that does not oblige the user to figure out what the appropriate hand movement is for the opening or closing action desired, and that can be operated with a great deal of simplicity. The present invention addresses these and other needs.